A. Field of Invention
This invention pertains to a pleated packaging useful for wrapping various objects, such as sandwiches, or other foodstuff, and method of using the same.
B. Description of the Prior Art
In U.S. Pat. No. 4,795,648, incorporated herein by reference, there is described a packaging made from a thin sheet which is pleated and the borders of its pleats are affixed to one another by various methods. The pleats are knife pleats. The dimensions of the pleats are selected to conform to the nature of the object to be packaged and with the distance between the welds. The pleats are fixed at the ends, and are free at the middle, such that when they are opened up they form a hollow shape which is suitable for wrapping round sandwiches and the like. The patent describes a method enabling this type of shape to be obtained from a flat sheet by making parallel knife pleats which give the folded wrapping a substantially planar configuration that is bulked up by unfolding.
In co-pending application Ser. No. 687,381 filed Apr. 18, 1991, entitled PLEATED PACKAGING WRAPPER FOR OBJECTS, a more generalized structure is described for pleated packaging. However, when the packaging constructed as described above was tested, it was found there was some difficulty in using the packaging to wrap certain objects especially if the objects were fragile such as, for example, sandwiches. Thus wrapping fragile objects required more training, and was time consuming.
Moreover, it was found that certain wrapping such as for hamburgers require reinforcement to protect the hamburger against crushing and to resist vertical forces.